Matsumoto Mao is suppose to become the new medical examiner and visit the USA at the age of 10. While there she is to study advanced placement 3rd year Forensics. she has an IQ of over 150.

Suddenly she becomes like an ordinary person confusing everybody, except Kyoko. A rush of bodies come in for autopsy. A middle aged man who apparently fell for a scaffolding at a construction site comes in. Mao begins the autopsy without a speck of the days exhaustion showing. She discoveries that he did not simply head his head while falling. Case impending..